Tris (hydroxymethyl) aminomethane salt of thioctic acid

ABSTRACT

The present invention concerns new compounds of anti-acidotic action such as the derivatives of tris (hydroxymethyl) aminomethane, of important therapeutic application.

United States Patent ['19] Salat et al.

[ 1 Feb. 27, 1973 [54] TRIS (HYDROXYMETHYL) AMINOMETHANE SALT OF THIOCTIC ACID [75] Inventors: Carlos Ferrer Salat, Jorge Ferrer Batlles, Juan Colome Riera, all of Barcelona, Spain [73] Assignee: Laboratorios Ferrer, S. L., Barcelona, Spain [22] Filed: Sept. 3, 1970 [21] Appl. No.: 69,225

Related U.S. Application Data [62] Division of Ser. No. 616,780, Dec. 17, 1967, Pat. No.

[30] Foreign Application Priority Data Feb. I7, 1966 Spain ..323,l95

[52] U.S. Cl. ..260/327 A, 260/251 R, 260/253,

424/250, 424/277 [51] Int. Cl. ..A6lk 27/00, C07d 7l/00 [58] Field of Search ..260/3 27 A [56] References Cited UNITED STATES PATENTS [57] ABSTRACT The present invention concerns new compounds of anti-acidotic action such as the derivatives of tris (hydroxymethyl) aminomethane, of important therapeutic application.

1 Claim, No Drawings TRIS (HYDROXYMETHYL) AMINOMETHANE SALT OF TIIIOCTIC ACID This application is a divisional application of applicants US. Patent application, Ser. No. 616,780, filed Feb. 17, 1967, now US. Pat. No. 3,562,273, patented Feb. 9, 1971.

Constant blood pH is essential for the development of vital processes of the human organism. However, the acidosis produced either by abnormal accumulation in blood of ketone groups originating from the abnormal catabolism of fatty acids together with a deficiency in the metabolism of carbohydrates, either by failure in the mechanism regulating the blood and extra-blood P In the first type of acidosis, the treatment can be directed to increase the pH and the alkali reserve, to promote the whole metabolism of the ketone bodies, or both, simultaneously. 1

In the second case, the treatment must be directed to increase the alkali reserve and to activate the extrablood regulator mechanisms.

In general, the treatments used up to now were directed to normalize the pH by increasing the alkali reserve.

For instance, use was made of sodium bicarbonate which acts exclusively as a blood buffer, but it shows the disadvantage of being contraindicated in the acidosis of respiratory or renal nature and being devoid of intracellular buffer action.

In 1959, Nahas introduced the organic amines, among which by its efficacy and non-toxicity the tris (hydroxymethyl) aminomethane or THAM, which not only acts as a plasmatic buffer but also as an intracellular buffer.

However, the THAM shows some disadvantages in relation to its administration since its solutions are too alkaline and may provoke digestive troubles. On the other hand, it is not active against the causes of the acidosis.

To correct such disadvantages in the treatment of acidosis we have directed our investigation towards the synthesis of THAM derivatives having more effective therapeutic properties and being better tolerated.

In this way we have synthesized a series of THAM derivatives with organic acids acting on acidosis. The mentioned compounds not only reestablish the pH but they are also active against the causes producing the changes, and they differentiate from the antiacidotic substances known so far.

The method of obtaining these compounds is essentially based on the direct reaction of the respective acid with tris (hydroxymethyl)amin'omethane, either in the fusion state or in a suitable solvent.

These compounds can also be obtained by reacting the salts of the components by means of double replacement in a solvent that is suitable in each particular case.

The invention is illustrated, by way of examination, by the following examples:

EXAMPLE 1 200 g. of theophylline and 500 cc. of water are heated to ebullition and added to 100 g. of chloroacetic acid and small portions of sodium hydroxide 30% without discontinuing agitation and heating strongly for 10 minutes. Then keep slow ebullition for another 30 minutes.

The solution is then cooled in a drier, then filtered, the resulting crystals are washed with slightly acidified water and, finally, desiccated. The crystals thus obtained correspond to theophylline acetic acid.

g. of theophylline acetic acid perfectly dried are pulverized with 50.9 g. of tris (hydroxymethyl) aminomethane in a mortar until a homogenous mixture is obtained. The mixture is immediately transferred to a steel container in oil bathand heated to l50-l75 C.

The mixture is constantly and vigorously agitated until a limpid liquid is obtained which is dropped, still scalding, into steel trays and, finally, is subjected to vacuum desiccation to preserve from moisture.

The desiccated product must be manipulated rapidly and in a very dry medium as it is very hygroscopic. In

'this way are obtained some 145 g. of tris (hydroxymethyl) aminomethane theophylline acetate.

EXAMPLE 2 26.0 g. of sodium theophylline acetate are dissolved in the smallest possible quantity of water, to which 15.8 g. of tris (hydroxymethyl) aminomethane hydrochloride is added.

Ebullition is maintained for 30 minutes; then 200 cc. of warm alcohol 96 are added, and the hot solution is filtered to separate the Na Cl thus formed. The resulting solution is vacuum evaporated until a pasty mass of crystals is detached and then treated with absolute alcohol; the evaporation to dryness is repeated to eliminate the remaining water.

The efficiency is 88 percent.

The product thus obtained has been identified as the trist (hydroxymethyl) aminomethane theophyllineacetate of molecular weight 359.3, empirical formula C H N O and structural formula:

0 I! l N NH? l l i HOHzC-C-CHzOH 0 N N 1......

White powder, hygroscopic, melting at C, very soluble in water and warm alcohol, sparingly soluble in cold alcohol, insoluble in chloroform, acetone, bencene and ether. In 0.05 M solution it has a pH of 6.4. Its absorption spectrum in ultraviolet in H Cl 0.1 N shows a maximum at 272 Mg.

EXAMPLE 3 In a double opening 500 cc. matrass are placed 14.4 g. of tris (hydroxymethyl) aminomethane finely powdered and cc. of absolute ethyl alcohol. The matrass is adjusted to a reflux cooler.

The mixture is heated in water-bath until the tris (hydroxymethyl) aminomethane is dissolvedv In the free end of the matrass is adjusted a separatory funnel containing a solution of 25 g. of thioctic acid in 125 cc. alcohol.

This solution is slowly dropped in the matrass for 30 minutes always maintaining the matrass contents in ebullition. Then the ebullition is maintained for another 10 minutes to complete the reaction.

The solution being still hot, it is carefully vacuum concentrated to avoid sudden elimination of the alcohol. It is cooled in the refrigerator for 3 to 4 hours, with occasional agitation to obtain crystallization.

The mixture is vacuum filtered and dried in the drying chamber at 60 C. for 1 hour.

The product is re-crystallized in alcohol at the rate of 4 cc. alcohol/g., then the crystals are washed with anhydrous ether and dried in the drying chamber at 60 C. A tris (hydroxymethyl) aminomethane thioctate, crystalline yellowish powder of 120 C. metling point, is obtained.

The efficiency is 87 percent.

EXAMPLE 4 15.8 g. of tris (hydroxymethyl) aminomethane hydrochloride are dissolved in the smallest possible quantity of water and 22.8 g. of sodium thioctate are previously added, dissolved in the smallest possible quantity of water.

The resulting solution in maintained in ebullition for 30 minutes and one part of the solvent is allowed to evaporate. Then it is allowed to cool, 200 cc. of alcohol are added and the mixture is heated again. The solution, still hot, is immediately filtered to separate the sodium chloride thus formed. The solution is slowly cooled in the refrigerator and the product becomes crystallized.

The product is vacuum filtered and dried, then recrystallized in alcohol as in Example 3. The efficiency is in the range of 80 percent but the mother waters of crystallization can be used for a new obtention.

The product obtained, the tris (hydroxymethyl) aminomethane thioctate, has the empirical formula: C 2H25O5NSz and it corresponds to the following structural formula:

The molecular weight is 327.5 and its melting point is 120 C.

It is a yellow crystalline powder, very soluble in water and in hot alcohol. It is sparingly soluble in cold alcohol and in warm acetone. It is insoluble in chloroform, benzene and ether. In 0.1 M aqueous solution it has a pH of 6.5. Its ultraviolet spectrum shows a maximum absorption of 335 my. in ethanol.

EXAMPLES 7.8 g. (1/20 mol) of tris (hydroxymethyl) aminomethane orotate is added in small portions to a solution containing 6 g. (1/20 mol) of THAM in 100 cc. of water.

The temperature is raised slowly to 80 C, with continuous agitation.

The solvent is evaporated to dryness, the product is washed with ether and vacuum dried again.

The efficiency is in the range of 94 percent.

The product thus obtained is a microcrystalline powder, soluble in water and in alcohol and insoluble in ether.

EXAMPLE 6 Small amounts of water are added to g. of sodium pangamate until complete dissolution.

On the other hand, 7.6 g. of tris (hydroxymethyl) aminomethane hydrochloride are dissolved in the smallest possible amount of water. The solutions are mixed and heated to ebullition.

96 alcohol is added to the necessary amount until the sodium chloride starts becoming insoluble, then 10 cc. of 96 alcohol is added.

The solution is filtered and the residue is washed with 96 alcohol.

Both filtrates are joined. The solution is evaporated to dryness with vacuum aid.

Efficiency is in the range of 96 percent.

A series of toxicologic, pharmacologic and clinical experiences have been carried out with the new compounds.

The LD 50 of tris (hydroxymethyl) aminomethane theophylline acetate in albino mice by oral route is 4.05 i 0.174 g./kg. and 2.45 i 0.145 g./kg. by intravenous route.

The LD 50 of tris (hydroxymethyl) aminomethane thioctate in mice is 506 i 4.71 mg. by oral route, 126.4 1 5.76 mg./kg. by intravenous route and 278 i 5.69 mg./kg. by intraperitoneal route.

This compound has also been experimented in rats. The LD 50 is 1600 i 168 mg./kg. by oral route, 345.2 i 27.1 mg./kg. by intravenous route and 365: 25.5 mg./kg. by intraperitoneal route.

All results are expressed according to the Reed- Muench method.

The buffer capacity of these compounds has been verified in dogs anesthetized with pentothal with acute experimental acidosis induced by iv injection of a solution of phosphates, ammonium chloride, lactic acid, etc. up to a pH of 7.2.

When the product is administered by intravenous route the pH return to normal values and the reserve expressed in bicarbonate is recuperated.

The study of the results of the administration of 50 mg./kg. of tris (hydroxymethyl) aminomethane thioctate to cats weighing 2 to 3 kg. showed no changes in blood pressure nor modification of the respiratory recording. The electrocardiogram was neither modified during or after administration.

The tris.(hydroxymethyl) aminomethane theophylline acetate can be considered, by its characteristics, as a complete antiacidotic product since it acts not only on the blood factors that regulate the pH but also on the cellular pulmonary and renal factors.

In acidosis of intracellular origin, the new compound acts as a proton acceptor neutralizing the intracellular hydrogen ions. In respiratory acidosis, the depressant action of tris (hydroxymethyl) aminomethane on the respiratory centers is counteracted by the stimulant action exerted by theophylline on. them. In renal acidosis, there is a synergism between the diuretic action of osmotic and tubular type of the tris (hydroxymethyl) aminomethane with that of glomerular type of the theophylline.

Clinically, the tris (hydroxymethyl) aminomethane theophylline-acetate is indicated in all types of toxic, respiratory or metabolic acidosis of tissular, pulmonary, plasmatic, or renal origin. Also in intoxications of medieamental origin produced by barbiturates, salicylic derivatives and the like, in which it facilitates the quick elimination of the toxic substances by renal route.

with troubles of the liver function or of the metabolism of glucides. Likewise, in acidoketosis by fever, vomiting, ketonuria, dehydratations, denutrition, alcoholism, diabetic acidosis, post-anesthetic acidosis, etc.

We claim:

1. A composition of matter, tris(hydroxymethyl)aminomethane salt of thiocticacid. 

